ATL: TEN - Post-Tropical - Discussion

[HurricaneRyan]

The Lindsay Lohan of invests keeps failing to develop I see.

[SuperMarioBros99thx]

This cyclone should be named, now. I can't hold of I storms being majors anymore and instead it had to be stopped.

[Hammy]

As it's now highly unlikely this develops, will the NRL keep the archive since it's been numbered, or disappear with the other invests?

[cycloneye]

Potential Tropical Cyclone Ten Discussion Number 7
NWS National Hurricane Center Miami FL AL102017
500 AM EDT Tue Aug 29 2017

The disturbance has developed a center that has been trackable
this evening though it is still not well-defined, since it
appears to be considerably elongated northeast-southwest. The
disturbance continues to display very cold, but extremely asymmetric
deep convection with all of the thunderstorm activity east of the
center due to strong vertical shear. Moreover, the convection is
showing no identifiable banding features. So the system is not yet
a tropical cyclone. Regardless of the label we use to describe this
hybrid system, maximum winds are around 35 kt based upon a Dvorak
classification from TAFB and observed winds just below that from
the NDBC Buoy 41013.

The initial motion of the disturbance is northeast at a faster rate
of about 10 kt. Continued acceleration is expected during the next
couple of days as a mid- to upper-level trough over the Great Lakes
moves closer to the system. The NHC forecast track takes the
disturbance across the North Carolina coastline today. By tonight,
the cyclone is forecast to move offshore and accelerate over the
Atlantic in the mid-latitude westerlies. The NHC track forecast lies
near the middle of the guidance envelope and is not substantially
changed from the previous advisory.

Given the poor organization of the disturbance and the strong wind
shear environment that it is embedded within, the chances of this
disturbance becoming a tropical cyclone have decreased to about a
coin flip. Nonetheless, the potential impacts of tropical-storm-
force winds across portions of North Carolina are likely today even
if the system does not become a tropical cyclone. The system is
expected to become extratropical in 24 hours or less when it
interacts with the aforementioned mid- to upper-level trough.
Significant strengthening as an extratropical cyclone is forecast
for a couple of days due to baroclinic forcing. No significant
change has been made to the NHC intensity forecast.

The track, intensity, and wind radii forecasts from 24 to 120 h are
based on guidance provided by NOAA's Ocean Prediction Center.

FORECAST POSITIONS AND MAX WINDS

INIT 29/0900Z 33.5N 78.5W 35 KT 40 MPH...POTENTIAL TROP CYCLONE
12H 29/1800Z 35.4N 76.0W 40 KT 45 MPH
24H 30/0600Z 38.0N 71.5W 50 KT 60 MPH...POST-TROP/EXTRATROP
36H 30/1800Z 39.5N 66.5W 60 KT 70 MPH...POST-TROP/EXTRATROP
48H 31/0600Z 41.0N 61.0W 70 KT 80 MPH...POST-TROP/EXTRATROP
72H 01/0600Z 44.5N 50.0W 50 KT 60 MPH...POST-TROP/EXTRATROP
96H 02/0600Z 50.0N 33.0W 40 KT 45 MPH...POST-TROP/EXTRATROP
120H 03/0600Z 55.0N 19.0W 30 KT 35 MPH...POST-TROP/EXTRATROP

$$
Forecaster Landsea

[SuperMarioBros99thx]

Potential Tropical Cyclone Ten Discussion Number 7
NWS National Hurricane Center Miami FL AL102017
500 AM EDT Tue Aug 29 2017

The disturbance has developed a center that has been trackable
this evening though it is still not well-defined, since it
appears to be considerably elongated northeast-southwest. The
disturbance continues to display very cold, but extremely asymmetric
deep convection with all of the thunderstorm activity east of the
center due to strong vertical shear. Moreover, the convection is
showing no identifiable banding features. So the system is not yet
a tropical cyclone. Regardless of the label we use to describe this
hybrid system, maximum winds are around 35 kt based upon a Dvorak
classification from TAFB and observed winds just below that from
the NDBC Buoy 41013.

The initial motion of the disturbance is northeast at a faster rate
of about 10 kt. Continued acceleration is expected during the next
couple of days as a mid- to upper-level trough over the Great Lakes
moves closer to the system. The NHC forecast track takes the
disturbance across the North Carolina coastline today. By tonight,
the cyclone is forecast to move offshore and accelerate over the
Atlantic in the mid-latitude westerlies. The NHC track forecast lies
near the middle of the guidance envelope and is not substantially
changed from the previous advisory.

Given the poor organization of the disturbance and the strong wind
shear environment that it is embedded within, the chances of this
disturbance becoming a tropical cyclone have decreased to about a
coin flip. Nonetheless, the potential impacts of tropical-storm-
force winds across portions of North Carolina are likely today even
if the system does not become a tropical cyclone. The system is
expected to become extratropical in 24 hours or less when it
interacts with the aforementioned mid- to upper-level trough.
Significant strengthening as an extratropical cyclone is forecast
for a couple of days due to baroclinic forcing. No significant
change has been made to the NHC intensity forecast.

The track, intensity, and wind radii forecasts from 24 to 120 h are
based on guidance provided by NOAA's Ocean Prediction Center.

FORECAST POSITIONS AND MAX WINDS

INIT 29/0900Z 33.5N 78.5W 35 KT 40 MPH...POTENTIAL TROP CYCLONE
12H 29/1800Z 35.4N 76.0W 40 KT 45 MPH
24H 30/0600Z 38.0N 71.5W 50 KT 60 MPH...POST-TROP/EXTRATROP
36H 30/1800Z 39.5N 66.5W 60 KT 70 MPH...POST-TROP/EXTRATROP
48H 31/0600Z 41.0N 61.0W 70 KT 80 MPH...POST-TROP/EXTRATROP
72H 01/0600Z 44.5N 50.0W 50 KT 60 MPH...POST-TROP/EXTRATROP
96H 02/0600Z 50.0N 33.0W 40 KT 45 MPH...POST-TROP/EXTRATROP
120H 03/0600Z 55.0N 19.0W 30 KT 35 MPH...POST-TROP/EXTRATROP

$$
Forecaster Landsea

I'm hoping that coin flip would result in... named storm (most likely to be STS) Irma. I won't hold back anymore about this storm, and i'm aware that this invest is so powerful even it could fight alot of shear on it and somewhat organizes to be sure. I'm sorry if i am insane 'bout this storm...

[mitchell]

I'm sorry if this question was already answered but what was the criteria that caused this system to stop being called "invest 92l" and to start being referred to by the NHC as "potential tropical cyclone"?

[RL3AO]

I'm sorry if this question was already answered but what was the criteria that caused this system to stop being called "invest 92l" and to start being referred to by the NHC as "potential tropical cyclone"?

Because it was likely to develop into a tropical cyclone and impact land within 48 hours. Calling it a PTC allows watches and warnings to be issued before a system officially develops.

[Happy Pelican]

Track actually bumped left a bit, may bring more rain, gusty winds, rip currents, high surf, etc. to the Northeast Coast

It's a real nasty day at the Jersey Shore. Ocean Is a mess, winds are gusting but no rain yet.

[weathaguyry]

Track actually bumped left a bit, may bring more rain, gusty winds, rip currents, high surf, etc. to the Northeast Coast

It's a real nasty day at the Jersey Shore. Ocean Is a mess, winds are gusting but no rain yet.

Yep, same story here on Long Island as well. Tides are also elevated. (Here are the tides for the beach I work at)

[junepath]

We are on the southern end of Hatteras Island. It rained a lot between yesterday morning and today, sometimes very hard. Winds were more intense Sunday night than they got yesterday, and they are totally still right now.

[WilmingtonSandbar]

At the mouth of the Cape Fear River in SE NC, and this is non-issue. We had steady rain yesterday, and last night, but nothing to cause anything beyond minor roadside flooding.

[capepoint]

Currently near Cape Lookout, very light winds, partly sunny, some rain yesterday and overnight but nothing unusual. Tide is slightly high, may be a foot or so above normal this afternoon at high tide but nothing different from an astronomical high tide. Did somebody say something about a storm today? lol

[cycloneye]

Potential Tropical Cyclone Ten Discussion Number 8
NWS National Hurricane Center Miami FL AL102017
1100 AM EDT Tue Aug 29 2017

Surface observations near and offshore the southern coast of North
Carolina indicate that an elongated circulation and pressure minimum
are located over Onslow Bay, but satellite imagery still shows no
signs of a well-defined center. In addition, a sharp wind shift,
associated with a front, extends northeastward across Pamlico and
Albemarle Sounds and the Outer Banks. Maximum winds remain 35 kt
for continuity's sake since there have been no recent observations
of sustained tropical-storm-force winds.

The disturbance has so far failed to become a tropical cyclone, and
since vertical shear is 30-40 kt and increasing, it appears that it
now has a low chance of doing so before it becomes extratropical
later today. Baroclinic energy from the approaching shortwave
trough should cause the extratropical cyclone to strengthen
significantly during the next day or two, and it is forecast to be
producing hurricane-force winds over the northwestern Atlantic by
36 hours. Gradual weakening is expected after that time until the
cyclone is absorbed on day 5. The track, intensity, and wind radii
forecasts continue to incorporate guidance provided by NOAA's Ocean
Prediction Center.

The disturbance is accelerating toward the northeast with an
initial motion of 045/15 kt, and it is likely to clear the Outer
Banks into the western Atlantic by late this afternoon. The system
is embedded in the mid-latitude westerlies, and it will be
interacting with a shortwave trough moving east of the Great Lakes
during the next couple of days. This will cause the disturbance to
continue accelerating toward the northeast or east-northeast over
the north Atlantic for the next 4 days. The cyclone is expected to
be absorbed by another extratropical low by day 5.

FORECAST POSITIONS AND MAX WINDS

INIT 29/1500Z 34.4N 77.2W 35 KT 40 MPH...POTENTIAL TROP CYCLONE
12H 30/0000Z 36.6N 73.8W 45 KT 50 MPH...POST-TROP/EXTRATROP
24H 30/1200Z 38.8N 69.0W 50 KT 60 MPH...POST-TROP/EXTRATROP
36H 31/0000Z 40.4N 63.8W 70 KT 80 MPH...POST-TROP/EXTRATROP
48H 31/1200Z 41.8N 58.4W 60 KT 70 MPH...POST-TROP/EXTRATROP
72H 01/1200Z 45.8N 45.8W 45 KT 50 MPH...POST-TROP/EXTRATROP
96H 02/1200Z 51.0N 29.5W 35 KT 40 MPH...POST-TROP/EXTRATROP
120H 03/1200Z...ABSORBED

$$
Forecaster Berg

[Chris_in_Tampa]

996mb. 35 knots of surface wind. (350°, from the N) First wind from significant levels when released from plane from the 832mb level, 5 knots (85°, from the E).

[Chris_in_Tampa]

Vortex:



URNT12 KNHC 291821
VORTEX DATA MESSAGE AL092017
A. 29/17:54:10Z
B. 29 deg 03 min N
094 deg 31 min W
C. 850 mb 1398 m
D. 37 kt
E. 101 deg 32 nm
F. 162 deg 33 kt
G. 086 deg 53 nm
H. 996 mb
I. 19 C / 1619 m
J. 21 C / 1620 m
K. 16 C / NA
L. NA
M. NA
N. 1345 / 8
O. 0.02 / 5 nm
P. AF302 2109A HARVEY OB 02
MAX OUTBOUND AND MAX FL WIND 44 KT 278 / 25 NM 18:04:10Z
CNTR DROPSONDE SFC WIND 350 / 35 KT



Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 29th day of the month at 18:21Z
Agency: United States Air Force
Aircraft: Lockheed WC-130J Hercules with reg. number AF96-5302
Storm Number & Year: 09 in 2017
Storm Name: Harvey (flight in the North Atlantic basin)
Mission Number: 21
Observation Number: 02
A. Time of Center Fix: 29th day of the month at 17:54:10Z
B. Center Fix Coordinates: 29°03'N 94°31'W (29.05N 94.5167W)
B. Center Fix Location: 25 statute miles (40 km) to the SE (131°) from Galveston, TX, USA.
C. Minimum Height at Standard Level: 1,398m (4,587ft) at 850mb
D. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 37kts (~ 42.6mph)
E. Location of the Estimated Maximum Surface Wind Inbound: 32 nautical miles (37 statute miles) to the E/ESE (101°) of center fix
F. Maximum Flight Level Wind Inbound: From 162° at 33kts (From the SSE at ~ 38.0mph)
G. Location of Maximum Flight Level Wind Inbound: 53 nautical miles (61 statute miles) to the E (86°) of center fix
H. Minimum Sea Level Pressure: 996mb (29.42 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 19°C (66°F) at a pressure alt. of 1,619m (5,312ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 21°C (70°F) at a pressure alt. of 1,620m (5,315ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 16°C (61°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Wind, Pressure and Temperature
N. Fix Level: 850mb
O. Navigational Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 5 nautical miles

Remarks Section:
Maximum Outbound and Flight Level Wind: 44kts (~ 50.6mph) which was observed 25 nautical miles (29 statute miles) to the W (278°) from the flight level center at 18:04:10Z
Dropsonde Surface Wind at Center: From 350° at 35kts (From the N at 40mph)

[Chris_in_Tampa]

With short range radar:

[CrazyC83]

000
URNT15 KNHC 291844
AF302 2109A HARVEY HDOB 16 20170829
183430 2806N 09438W 8330 01599 0006 +171 +161 294030 031 035 001 00
183500 2806N 09436W 8330 01598 0008 +171 +146 289032 033 034 001 00
183530 2805N 09434W 8326 01604 0006 +178 +142 284031 032 034 001 03
183600 2805N 09432W 8326 01603 0004 +179 +143 283030 032 /// /// 03
183630 2806N 09432W 8336 01791 0138 +168 +161 291029 032 029 001 00
183700 2808N 09432W 8326 01595 0093 +178 +160 284028 029 029 003 00
183730 2810N 09432W 8327 01593 9990 +181 +164 284029 030 031 001 00
183800 2811N 09432W 8332 01586 9989 +183 +161 283028 029 031 002 00
183830 2813N 09432W 8327 01589 9988 +181 +163 283024 028 033 001 00
183900 2814N 09432W 8332 01584 9989 +180 +164 285023 024 032 001 00
183930 2816N 09432W 8326 01591 9986 +183 +163 284023 023 034 001 00
184000 2818N 09432W 8329 01587 9985 +183 +165 283022 023 035 001 00
184030 2819N 09432W 8330 01586 9987 +180 +166 281023 023 035 001 00
184100 2821N 09432W 8328 01586 9985 +182 +165 281022 023 035 001 00
184130 2823N 09432W 8330 01584 9982 +185 +161 280021 022 034 001 03
184200 2824N 09432W 8328 01584 9982 +185 +155 279021 021 036 000 00
184230 2826N 09432W 8331 01582 9980 +185 +160 278021 021 037 001 00
184300 2828N 09432W 8328 01583 9979 +189 +158 279022 023 039 001 00
184330 2829N 09432W 8330 01582 9978 +188 +161 274021 023 038 001 00
184400 2831N 09432W 8331 01581 9979 +190 +160 272019 020 039 000 00
$$
;

[CrazyC83]

000
URNT15 KNHC 291853
AF302 2109A HARVEY HDOB 17 20170829
184430 2833N 09432W 8328 01582 9975 +190 +162 272018 019 040 000 00
184500 2834N 09432W 8330 01580 9974 +193 +159 274020 020 040 000 00
184530 2836N 09432W 8329 01581 9972 +196 +153 276020 020 042 000 00
184600 2837N 09432W 8330 01578 9973 +195 +154 278020 020 044 001 00
184630 2839N 09432W 8328 01581 9970 +195 +156 277019 019 046 000 00
184700 2841N 09432W 8330 01578 9970 +198 +158 283019 019 045 001 00
184730 2842N 09431W 8331 01576 9967 +200 +159 287019 020 046 001 00
184800 2844N 09431W 8330 01577 9966 +200 +160 294017 019 045 001 00
184830 2846N 09431W 8328 01577 9963 +203 +157 296015 016 046 001 03
184900 2847N 09430W 8326 01578 9959 +207 +159 300016 019 045 001 00
184930 2849N 09429W 8330 01574 9958 +208 +160 308024 025 046 001 00
185000 2850N 09428W 8328 01572 9954 +210 +165 307024 026 045 001 00
185030 2851N 09427W 8329 01570 9953 +208 +167 304021 023 044 001 00
185100 2853N 09426W 8329 01570 9950 +210 +165 312017 019 041 001 00
185130 2854N 09425W 8333 01565 9945 +216 +163 312018 020 039 001 03
185200 2855N 09424W 8332 01569 9947 +216 +160 293013 016 033 001 00
185230 2857N 09422W 8331 01569 9944 +218 +160 271015 017 024 001 00
185300 2858N 09421W 8328 01568 9945 +215 +158 228019 019 023 000 00
185330 2900N 09420W 8332 01563 9945 +215 +158 210019 019 025 000 00
185400 2901N 09419W 8330 01565 9943 +215 +159 203020 020 025 001 03
$$
;

46 kt SFMR (likely high due to shoaling).

[CrazyC83]

000
URNT15 KNHC 291903
AF302 2109A HARVEY HDOB 18 20170829
185430 2903N 09420W 8331 01561 9940 +215 +158 187021 021 025 001 03
185500 2904N 09421W 8331 01559 9944 +205 +165 168018 020 026 000 00
185530 2904N 09423W 8331 01555 9946 +196 +176 155012 016 024 001 00
185600 2904N 09425W 8327 01560 9948 +192 +180 148001 009 023 002 00
185630 2903N 09427W 8333 01555 9949 +190 +178 327007 011 028 001 00
185700 2902N 09428W 8333 01557 9946 +198 +170 312018 023 028 002 03
185730 2900N 09428W 8326 01566 9940 +215 +158 302026 027 /// /// 03
185800 2859N 09426W 8328 01564 9936 +225 +143 284026 027 033 001 00
185830 2859N 09424W 8332 01561 9937 +227 +138 270022 026 033 001 00
185900 2858N 09422W 8334 01563 9940 +227 +145 262015 021 022 001 00
185930 2858N 09420W 8328 01569 9945 +218 +155 235018 019 027 002 03
190000 2858N 09418W 8334 01565 9950 +214 +150 215020 020 027 001 00
190030 2857N 09416W 8329 01571 9953 +211 +153 212021 022 027 000 00
190100 2857N 09414W 8327 01576 9957 +211 +154 215021 021 026 000 03
190130 2857N 09412W 8330 01575 9960 +205 +157 213021 022 027 000 00
190200 2857N 09412W 8330 01575 9963 +205 +158 205021 021 028 000 00
190230 2856N 09408W 8330 01577 9963 +203 +162 204022 023 029 000 03
190300 2856N 09406W 8327 01581 9967 +198 +171 201020 022 030 001 00
190330 2855N 09404W 8328 01581 9968 +200 +168 196020 021 032 000 00
190400 2855N 09403W 8330 01580 9970 +197 +166 188021 021 032 000 00
$$
;

Center is fairly broad. Pressure 994mb.

[CrazyC83]

000
URNT15 KNHC 291913
AF302 2109A HARVEY HDOB 19 20170829
190430 2855N 09403W 8330 01580 9972 +195 +164 186022 023 032 001 00
190500 2854N 09359W 8330 01581 9973 +198 +157 186023 024 034 000 00
190530 2854N 09357W 8330 01582 9973 +198 +156 183024 024 035 000 03
190600 2854N 09355W 8328 01586 9973 +200 +153 185025 025 035 001 00
190630 2853N 09353W 8330 01583 9974 +200 +150 185025 025 034 001 00
190700 2853N 09352W 8328 01586 9974 +201 +147 186024 025 035 000 00
190730 2853N 09350W 8327 01588 9975 +200 +152 185024 025 035 000 00
190800 2852N 09348W 8330 01586 9978 +198 +158 184026 027 035 000 00
190830 2852N 09346W 8328 01588 9980 +196 +157 185026 027 035 000 00
190900 2852N 09344W 8328 01591 9982 +195 +157 184026 027 035 000 00
190930 2851N 09343W 8328 01592 9985 +196 +155 184027 027 035 001 00
191000 2851N 09341W 8328 01594 9990 +190 +158 183028 028 034 000 00
191030 2850N 09339W 8330 01594 9993 +185 +159 185030 030 035 000 00
191100 2850N 09337W 8330 01594 9994 +187 +158 190030 030 033 001 00
191130 2850N 09335W 8332 01595 9998 +184 +158 191030 031 034 001 00
191200 2849N 09333W 8326 01604 0003 +178 +160 191028 030 033 001 00
191230 2849N 09332W 8330 01600 0005 +180 +155 187030 030 032 001 00
191300 2849N 09330W 8326 01606 0004 +182 +155 187030 031 033 000 00
191330 2848N 09328W 8330 01603 0006 +183 +153 189029 030 031 002 00
191400 2848N 09328W 8330 01603 0008 +184 +146 189030 031 031 001 00
$$
;